constant2 0.0.13

Quick Links

Usage

Version Changed 0.0.9: All nested class now has to inherit from Constant or its subclass:

# WRONG!
class ItemType(Constant):
    class Weapon:
        id = 1

# CORRECT
class ItemType(Constant):
    class Weapon(Constant):
        id = 1

# or
class Item(Constant):
    pass

class ItemType(Constant):
    class Weapon(Item):
        id = 1

Usage:

from constant2 import Constant

class Food(Constant):

    class Fruit(Constant):
        id = 1
        name = "fruit"

        class Apple(Constant):
            id = 1
            name = "apple"

            class RedApple(Constant):
                id = 1
                name = "red apple"

            class GreenApple(Constant):
                id = 2
                name = "green apple"

        class Banana(Constant):
            id = 2
            name = "banana"

            class YellowBanana(Constant):
                id = 1
                name = "yellow banana"

            class GreenBanana(Constant):
                id = 2
                name = "green banana"

    class Meat(Constant):
        id = 2
        name = "meat"

        class Pork(Constant):
            id = 1
            name = "pork"

        class Beef(Constant):
            id = 2
            name = "beef"

food = Food()

You can visit it’s data or child class data in these way:

# Use class
>>> Fruit.Items() # .Items() return it's data
[('id', 1), ('name', 'fruit')]

>>> Fruit.Keys() # .Keys() return keys
['id', 'name']

>>> Fruit.Values() # .Values() return values
[1, 'fruit']

>>> Fruit.ToDict() # return data in a dict
{'id': 1, 'name': 'fruit'}

# use instance
>>> food.items() # .Items() return it's data
[('id', 1), ('name', 'fruit')]

>>> food.keys() # .keys() return keys
['id', 'name']

>>> food.values() # .values() return values
[1, 'fruit']

>>> food.to_dict() # return data in a dict
{'id': 1, 'name': 'fruit'}

# iterate on all nested class
>>> Fruit.Subclasses(sort_by='id')
[class Apple, class Banana]

# get first nested class that kls.id == 1
# useful when you need reverse lookup
>>> Fruit.GetFirst('id', 1)
class Apple

# get all child class that kls.id == 1
>>> Fruit.GetAll('id', 1)
[class Apple, ]

And it provides built-in I/O methods allow you to dump these data in to a dictionary.

>>> data = Food.dump()
>>> data
{
    "Food": {
        "Fruit": {
            "Apple": {
                "GreenApple": {
                    "__classname__": "GreenApple",
                    "id": 2,
                    "name": "green apple"
                },
                "RedApple": {
                    "__classname__": "RedApple",
                    "id": 1,
                    "name": "red apple"
                },
                "__classname__": "Apple",
                "id": 1,
                "name": "apple"
            },
            "Banana": {
                "GreenBanana": {
                    "__classname__": "GreenBanana",
                    "id": 2,
                    "name": "green banana"
                },
                "YellowBanana": {
                    "__classname__": "YellowBanana",
                    "id": 1,
                    "name": "yellow banana"
                },
                "__classname__": "Banana",
                "id": 2,
                "name": "banana"
            },
            "__classname__": "Fruit",
            "id": 1,
            "name": "fruit"
        },
        "Meat": {
            "Beef": {
                "__classname__": "Beef",
                "id": 2,
                "name": "beef"
            },
            "Pork": {
                "__classname__": "Pork",
                "id": 1,
                "name": "pork"
            },
            "__classname__": "Meat",
            "id": 2,
            "name": "meat"
        },
        "__classname__": "Food"
    }
}

>>> Food = Constant.load(data)

Install

constant2 is released on PyPI, so all you need is:

$ pip install constant2

To upgrade to latest version:

$ pip install --upgrade constant2